Liquid fuel vaporizer



Jan. 22, 1952 J. 5. CLARKE ET AL LIQUID FUEL VAPORIZER Filed Dec.

4 Sheets-Sheet l Z 210 1275016 J. 6. Gila/b 1.25. Gl e J. $.CLARKE ET AL Jan. 22, 1952 LIQUID FUEL VAPORIZER 4 Sheets-Sheet 2 Filed Dec. 5, 1949 liq/061217025 QI 5, Ola/nice H 61 1952 J. s. CLARKE ET AL 2,583,416

LIQUID FUEL VAPORIZER Filed Dec. 5, 1949 4 Sheets-Sheet 5 Clarke fl .E. Gl eyop 42 .17. Gfipa/rci Jan. 22, 1952 J. s. CLARKE ET AL 2,583,416

LIQUID FUEL VAPORIZER Filed Dec. 5, 1949 4 Sheets-Sheet 4 vaporising tube.

Patented Jan. 22, 1952 UNITED STATE LIQUID FUEL VAPORIZER John Stanley Clarke, Blacko, near Nelson, William Edmund Gregory, Burnley, and Alan Joseph Gerrard, Blackburn, England, assignors to Joseph Lucas Limited, Birmingham, England Application December 5, 1949, Serial No. 131,086 In Great Britain December 7, 1948 4 Claims.

This invention has for its object to provide an improved liquid fuel vaporiser adapted for use more particularly in the combustion chamber-sci liquid fuel prime movers, such as jet-propulsion engines or turbines.

In the accompanying drawingsi Figure 1 is a sectional side elevation illustrating one embodiment of the invention, and Figure 2 is a cross section on the line 2--2 of Figure 1.

Figure 3 is a sectional side elevation illustrating another embodiment of the invention, and Figure 4 is a fragmentary sectional side elevation illustrating a modification of the construction shown in Figure 3.

Referring to Figures 1 and 2, there is mounted on any convenient carrier at (which may be perforated), an annular arrangement of equi-spaced liquid fuel injection nozzles b, preferably of the swirl type, liquid fuel being supplied to the nozzles along pipes c from a chamber 11 secured to one side of the carrier and supplied with fuel from a pump or other source by a pipe e.

Coaxially with each nozzle 11 is provided a Each such tube comprises a pair of straight (inner and outer) coaxial tubes 1, g, the outer one being closed at its ends. Also at the entrance h to the inner tube 1 provision is made for the admission of a restricted amount of air. The mixture of sprayed fuel and air passes first along the inner tube, and on reaching the opposite end it returns along the outer tube.

At the end of each outer tube adjacent to the associated nozzle, an outlet 2' is provided, and concentrically with all the tubes is mounted a primary combustion chamber 7'. This latter is of short hollow cylindrical form and is open at one end. The entrances to the chamber from the vaporising tubes are provided in the periphery of the chamber, and the arrangement is such that the mixture of air and fuel from the tubes enters the chamber tangentially.

0n the axis of the carrier a provision is also made for the admission of a stream of air from the surrounding region through a perforated nozzle is of conical or other convenient form, an open air chamber m being provided between this nozzle and the chamber it above mentioned. Air from the surrounding region first enters the chamber m, and thence passes to the nozzle 70. The open side of the combustion chamber a faces the air nozzle 70, and (if desired) a deflecting plate may be mounted on this nozzle to prevent direct access of the air stream to the interior of the chamber The assembly above described is intended t prime mover. The arrangement is such that the fuel sprayed by the nozzles b'into the vaporising tubes is mixed with sufficient air to maintain combustion in the primary combustion chamber a. The issuing gases then pass into the main combustion chamber where admixture is effected with the air supplied to themain chamber for completion of the combustion process. Further air also may be supplied at a later stage from a jacket surrounding the main combustion chamber.

The principal object of the invention is to eifect complete combustion of the fuel over a wide range of air/fuel ratios, and to minimise risk of extinction of the flame during temporary abnormal conditions. By our invention this requirement is met in a very simple and satisfactory manner, as the primary combustion chamber 1 provides a protected region in which combustion can continue when the condition in the main chamber is such as may result in temporary extinction of the flame therein.

The invention is not, however, restricted to the example above described, as the constructional details may be varied. Also for some purposes a single pair only of tubes f, g, may be used, though for most purposes a plurality of such tubes is desirable, if not necessary.

In the example shown in Figure 3, vaporising tubes J of substantially U-form are used instead of the pairs of concentric straight tubes above described. Further instead of the above mentioned perforated conical nozzle k, an annular air nozzle is provided, this being formed by a plate n secured on and spaced from the carrier a. In other respects this construction is essentially similar to the one shown in Figures 1 and 2, and corresponding parts are indicated by the same reference letters.

As previously mentioned the burner is intended to be mounted coaxially within a combustion chamber, and in Figure 3, this is indicated by 0, the combustion chamber being surrounded by an air jacket 11.

In Figure 4 is shown a modification of theconstruction shown in Figure 3. The pipes c are supplied from a hollow fitting q which is connected to the fuel supply pipe e, and in association with this fitting is mounted a pilot (or igniting) burner r supplied by a pipe s. On the carrier a is mounted a plate 'n forming part of an annular air nozzle as above described. From the carrier it extends an air pipe 15 which passes through the combustion chamber 7' and terminates in a hollow and perforated cover piece it at the closed front end of the combustion chamber 1'. The air flowing through the pipe t and the cover piece it serves to minimise any tendency for solid carbon to be deposited on the front end of the said combustion chamber 9'. In other respects the construction shown in Figure 4 is essentially similar to that shown in Figure 3.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. A liquid fuel vaporiser comprislng in combination at least one fuel injection nozzle, a short cylindrical primary combustion chamber which is open at one end, and which is provided at its periphery with at least one tangentially arranged inlet for admitting to said chamber a mixture of Iu l .from said nozzle and air, at least one vaporising tube leading from said nozzle to said inlet .for conducting the mixture to said inlet,

Said vaporising tube being arranged to extend in which said vaporising tube comprises a pair of straight tubes arranged coaxially one within the other, one end of the outer tube being connected to the tangentially arranged inlet of said chamber, and said fuel injection nozzle being located at .one end of the inner tube.

' '3. A liquid fuel vaporiser as claimed in claim 1, in which said vaporising tube is of substantially U-form, and has a part extending from said fuel injection nozzle alongside the periphery of said chamber.

4. A liquid fuel vaporiser as claimed in claim 1 and having an air tube extending longitudinally through said chamber with one end of said air tube situated adjacent to the closed end of said chamber, and .a perforated cover piece at this end of said air tube.

JOHN STANLEY CLARKE. WILLIAM EDMUND GREGORY. ALAN JOSEPH GERRARD.

REFERENCES CITED The. iollowins refere c ar of r cord .in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 2,136,727 Pirich Nov. 1-5, 1938 2,411,663 McCollum Nov. 26, 1946 

